Alcohol abuse enhances pulmonary edema in acute respiratory distress syndrome.

BACKGROUND: Pulmonary edema is a cardinal feature of the life-threatening condition known as acute respiratory distress syndrome (ARDS). Patients with chronic alcohol abuse are known to be at increased risk of developing and dying from ARDS. Based upon preclinical data, we hypothesized that a history of chronic alcohol abuse in ARDS patients is associated with greater quantities and slower resolution of pulmonary edema compared with ARDS patients without a history of alcohol abuse. METHODS: A PiCCO transpulmonary thermodilution catheter was inserted into 35 patients within 72 hours of meeting American European Consensus Criteria definition of ARDS. Pulmonary edema was quantified as extravascular lung water (EVLW) and measured for up to 7 days in 13 patients with a history of chronic alcohol abuse and 22 patients without a history of chronic alcohol abuse. RESULTS: Mean EVLW was higher in patients with a history of chronic alcohol abuse (16.6 vs. 10.5 ml/kg, p < 0.0001). Patients with alcohol abuse had significantly greater EVLW over the duration of the study (RM-ANOVA p = 0.003). There was a trend towards slower resolution of EVLW in patients with a history of alcohol abuse (a decrease of 0.5 ml/kg vs. 2.4 ml/kg, p = 0.17) over the study period. A history of alcohol abuse conferred a greater than 3-fold increased risk of elevated EVLW [OR 3.16, (1.26 to 7.93)] using multivariate logistic regression analysis. CONCLUSIONS: In patients who develop ARDS, alcohol abuse is associated with greater levels EVLW and a trend towards slower resolution of EVLW. Combined with mechanistic and preclinical evidence linking chronic alcohol consumption and ARDS, targeted therapies should be developed for these patients.

Accurate characterization of extravascular lung water in acute respiratory distress syndrome.

OBJECTIVES: Measurements of extravascular lung water (EVLW) correlate to the degree of pulmonary edema and have substantial prognostic information in critically ill patients. Prior studies using single indicator thermodilution have reported that 21% to 35% of patients with clinical acute respiratory distress syndrome (ARDS) have normal EVLW (<10 mL/kg). Given that lung size is independent of actual body weight, we sought to determine whether indexing EVLW to predicted or adjusted body weight affects the frequency of increased EVLW in patients with ARDS. DESIGN: Prospective, observational cohort study. SETTING: Medical and surgical intensive care units at two academic hospitals. PATIENTS: Thirty patients within 72 hrs of meeting American-European Consensus Conference definition of ARDS and 14 severe sepsis patients without ARDS. INTERVENTIONS: None. MEASUREMENT AND MAIN RESULTS: EVLW was measured for 7 days by PiCCO transpulmonary thermodilution; 225 measurements of EVLW indexed to actual body weight (ActBW) were compared with EVLW indexed to predicted body weight (PBW) and adjusted body weight (AdjBW). Mean EVLW indexed to ActBW was 12.7 mg/kg for ARDS patients and 7.8 mg/kg for non-ARDS sepsis patients (p < .0001). In all patients, EVLW increased an average of 1.1 +/- 2.1 mL/kg when indexed to AdjBW and 2.0 +/- 4.1 mL/kg when indexed to PBW. Indexing EVLW to PBW or AdjBW increased the proportion of ARDS patients with elevated EVLW (each p < .05) without increasing the frequency of elevated EVLW in non-ARDS patients. EVLW indexed to PBW had a stronger correlation to Lung Injury Score (r2 = .39 vs. r2 = .17) and PaO2/FiO2 ratio (r2 = .25 vs. r2 = .10) than did EVLW indexed to ActBW. CONCLUSIONS: Indexing EVLW to PBW or AdjBW reduces the number of ARDS patients with normal EVLW and correlates better to Lung Injury Score and oxygenation than using ActBW. Studies are needed to confirm the presumed superiority of this method for diagnosing ARDS and to determine the clinical treatment implications.

Seasonal variation in the epidemiology of sepsis.

OBJECTIVE: We sought to investigate seasonal and regional variability in the epidemiology of sepsis and to identify underlying associations based on geography and seasonal viral infections. Understanding seasonal or regional variations may improve knowledge of sepsis epidemiology and pathophysiology and could affect healthcare planning and resource allocation. DESIGN: Retrospective cohort study using the National Hospital Discharge Survey to identify cases of sepsis, severe sepsis, influenza, and viral pneumonia using ICD-9-CM codes. Incidence rates are reported as mean cases frequencies per season per 100,000 as calculated by normalization to the 2000 U.S. Census. SETTING: Acute-care nonfederal U.S. hospitals. PATIENTS: Patients hospitalized between 1979 and 2003 in acute-care nonfederal U.S. hospitals with a diagnosis of sepsis or viral respiratory infection. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: The seasonal incidence rate of sepsis increased 16.5% from a low of 41.7 in the fall to a high of 48.6 cases per 100,000 in the winter (p<.05). Similarly, seasonal rates for severe sepsis statistically increased 17.7% from fall to winter at 13.0 and 15.3 cases per 100,000, respectively. The greatest change in sepsis incidence occurred with respiratory sources, increasing 40% during the winter compared with the fall (p<.05). Seasonal variations in viral respiratory infections paralleled changes in sepsis incidence but did not fully account for the changes. The greatest seasonal change in sepsis rates occurred in the Northeast (+30%). Sepsis case-fatality rates were 13% greater in the winter compared with the summer (p<.05) despite similar severity of illness. CONCLUSIONS: The incidence and mortality of sepsis and severe sepsis are seasonal and consistently highest during the winter, predominantly related to respiratory sepsis. Seasonal changes in sepsis incidence vary according to geographic region. The mechanisms underlying these differences require further investigation.

The epidemiology of sepsis in patients with malignancy.

STUDY OBJECTIVES: To evaluate the longitudinal epidemiology of sepsis in patients with a history of cancer and to specifically examine sepsis-related disparities in risk or outcome. DESIGN: Sepsis cases from 1979 through 2001 using a nationally representative sample of nonfederal acute-care hospitalizations in the United States (the National Hospital Discharge Survey) integrated with cancer prevalence from the Surveillance, Epidemiology, and End Results database. SETTING: Eight hundred fifty-four million acute-care hospitalizations and 8.9 million patients with cancer. PATIENTS OR PARTICIPANTS: Patients with a history of cancer hospitalized with a diagnosis of sepsis. MEASUREMENTS AND RESULTS: From 1979 to 2001, there were a total of 1,781,445 cases of sepsis in patients with cancer, yielding a mean annual incidence rate of 1,465 cases per 100,000 cancer patients and a relative risk [RR] of 9.77 compared to noncancer patients (95% confidence interval [95% CI], 9.67 to 9.88). In contrast to the absolute number of cases, the incidence rate of sepsis decreased over time, from a peak of 1,959 cases per 100,000 cancer patients in 1987 to 995 cases per 100,000 in 2001. The distribution of infectious sources causing sepsis was associated with the type of malignancy. White cancer patients had a lower risk for sepsis compared to nonwhites (African-American RR, 1.28; 95% CI, 1.16 to 1.40) and other races (RR, 1.47; 95% CI, 1.22 to 1.72); and male cancer patients had a higher risk for sepsis compared to female cancer patients (male RR, 1.17; 95% CI, 1.10 to 1.23). Cancer was an independent predictor of death among sepsis patients by multivariable analysis (adjusted odds ratio for death, 1.98; 95% CI, 1.97 to 1.99). CONCLUSIONS: Patients with a history of cancer are at increased risk for acquiring and subsequently dying from sepsis, compared to the general population, although incidence and fatality rates are decreasing over time. There are significant racial and gender disparities in the incidence and outcome of sepsis among cancer patients that require explanation.